I contacted Schmich via email and she claims the quote. How it got attached to Roosevelt is a complete mystery to her. I imagine it somehow got attached due to the Vonnegut apeech.
Great quotes have a way of getting themselves attached to famous people. It sounds better if it is attached to Eleanor Roosevelt than to "Mary Schmich." A perfect example is the '60s quote, "You can't trust anyone over thirty." It has been attributed to everyone from Abbe Hoffman, Mark Rudd, and Jerry Rubin but was actually attributed to a person named Jack Weinberg.
The internet is full of misquotes, misattributions, and spurious sayings.
Thanks for your great help again.
I suppose the author of her quote on this site has to be corrected. I can't put here the right link because I have not been registered for more than 10 days.